The Paleolithic lifestyle (PL) intervention during radiotherapy consists of daily outdoor walks or bike rides of at least 30 min duration, preferably done at noon to maximize vitamin D production, and the adoption of a Paleolithic diet. For the outdoor activity, patients were told to not use sun screen. The Paleolithic diet prescription emphasized the consumption of fatty meats and organ meats from humanely raised animals, wild-caught fish, eggs, nuts and seeds, algae, spices, vegetables and fruits. Excluded were processed foods, grains of all types, legumes, vegetable oils except for native coconut and olive oil and dairy products except for ghee. No dietary supplements were allowed. Patients were supposed to start the PL intervention at least two days prior to the first irradiation and to protocol their food consumption on two days during the first week on the diet. They were also asked about their compliance to the PL intervention at each weekly measurement appointment.

This group is on a standard diet while receiving radiotherapy.

Standard curative radiotherapy

Used to measure feasibility. The intervention is rated as feasible if dropout rate is <30%

Measured on a bioimpedance scale (seca mBCA, seca Deutschland, Hamburg, Germany)

Difference between final (average 5 weekks) and baseline 25-hydroxyvitamin D level

Change between baseline and final (average 5 weeks) beta-hydroxybutyrate levels